Time indicating system



May 21, 1935. N ANDERSON 2,001,831

v TIME INDICATING SYSTEM Filed May 17, 1932 i 2 Sheets-Sheet 1 lNVENTORATTORNEY N. AN SO IME INDICATING SYSTEM Fi O OOuuUuv l7 JOOCOOoooooooooboooooooou- M 2 et 000000000 ooooooooooooooooooooooooooooooooouwu eet 2 JOOOOOOOOOOooooooooooooooooooooOoooooooooooooooooooU oooc 0000000 0oooooooooooooooooo ooooooooooo oooc 2 00000000 ooooooooooooooooooooooooooooooooooo oooooooooo oooooooooooooooooo ooooooooooooo oooc0000000000 I 00000000000000000 0 000000000000000 0006 00000000 0oooooooooodoooooo 0000000000 0000: 0000000 0000000000000W00 000000000000000C 25 oooooooooooooooooo ooooooooooo ooooooo oooc 00 0000000000000000000000000 0000000 000C 000 00000000 o 000 00000000 00 oooc000000000000000000 000000 0000000000 000( oocoo ooooooooo 0000000 0000000 000000000 00000000 00 00000 0 0000000 0 0000000 00 00000 000000000000000 00 00000 000000000 0 0000000 o0 00000 00000000 0 0000000 0000000 000 000000 0 0000000 00 00000 000 00000 0' 0000000 00 00000 00000000 0 000000 oo g 00000 000 000 0 0.000 00 oo ooo 000 0000 00 00000 0000000 00 000 00 0000 00 00000 00 0000 on 0000 00 00000 00 00 0000 0000000 000 00.0 00 00000 00 00000 000 00 00 0000 00 ToR 4 ATTORNEYPatented May 21, 1935 I UNITED STATES PATENT OFFICE amssi TIME mmca'rmcsrs-mm Emil N. Anderson, Oak Park, 111., assignor to American Telephoneand Telegraph Company, a corporation of New York Application May 17,1932, Serial No. 611,907

15 Claims. (Cl. 161-19) This invention relates to measuring devices, atarget member 2 which fits inside of case I and and more particularly tomeans for indicating the is hinged at one end to said case, a drivingshaft termination of the predetermined timing periods '3, a driving gear4, a tripping cam 5, a clutch of telephone conversations. means 6. aclutch control means 1, a spring latch 5 In telephone systems it is atpresent custom- 8, a hinge spring 9, and a reset spring In. The 5 ary tocharge for coin box calls on a message target member is hinged orpivoted at one end rate basis. In the case of such calls it issomewithin the case by means of shaft ii, the sides of times necessaryto charge for what is generally the target member being directlyadjacent the known as overtime. In other words, a certain sides of thecase. Hinge spring 9 is wound l0 charge is made for each completed calllasting .around shaft II, the upper end'of said spring 10 apredetermined period of time or less, for exbeing adapted to pressagainst the top of the tarample, five minutes, and an overtime charge isget member, and the lower member thereof being made for each additionalpredetermined period adapted to press against the bottom of case I. g oftime during which the call lasts. At the ter- By reason of thisarrangement hinge spring 9 l5 mination of the first and of eachadditional timtends to cause the front end of the target member ingperiod the calling party is notified that if he to protrude above thefront of the case as shown desires to continue the call, he must depositanin Fig. 1. Near the bottom of the case is a bar other coin. member I2which extends toward the center of It has heretofore been suggested inconnection said case and is so positioned with respect to with systemsfor timing telephone calls that an spring latch 8 that when the targetmember is 20 individual register be provided for each cord cirpresseddown said spring latch engages said bar cult of a telephone switchboardfor timing each member. The movement of the target member connectioncompleted by the use of the correin being pressed down compresses hingespring 9. sponding cord circuit, a plurality of said regis- As a result,when the target member is pressed ters being associated with a common,continudown and spring latch 8 engages bar member i2, 25 ously rotating,driving shaft and each individual the target member is held down inopposition to register being provided with means for control-. the forceexerted by hinge spring 9. It can be ling its operation. seen from aninspection of Fig. 1 that said target One object of this invention is toprovide an member is exposed to view when it protrudes efllcient andinexpensive time indicator for use from the top of case I, and is hiddenfrom view 30 in connection with such systems. Another obwhen it ispressed down to its normal position ject is to provide such a timeindicator which emwithin said case. bodies means for automaticallycalling the at- Driving shaft 3 is adapted to be rotated contention ofthe operator to the termination of each tinuously at a constant speed,for example, by

such timing period. Other objects and features means of a synchronousmotor such as that dis- 35 of the invention will be apparent from thedeclosed, for example, by Patents Nos. 1,283,432, tailed descriptionhereinafter set forth. 1,283,433 and 1,283,435 issued to Henry E. War-Figure 1 of the drawing is a side view of the ren on October 29, 1918.Driving gear 4 is time indicator-with certain of its parts shown inmounted on shaft 3 and is adapted to rotate dotted lines; Fig. 2 is aside view of the target therewith. Tripping cam 5 is fastened to one 0member, which serves also as the top of the time end of hub i3 which inturn is loosely and slidindicator, with parts thereof broken away toably mounted on shaft 3. Spring i4 is wound show the spring latch andthe clutch control around shaft 3 between gear 4 and cam 5, and means;Fig. 3 is a side view of the lower part of normally keeps said gear andsaid cam from the time indicator with the side of the case reengagingeach other. Both gear 4 and cam 5 5 moved; Fig. 4 is a bottom view ofthe time indiare of the crown gear type-that is, the teeth cator in itsoperative condition; Fig. 5 is an enprotrude from the inner facesthereof. Fastened larged detailed view of the rotating parts, the to theperiphery of cam 5 is a tripping member clutch means and the resetmeans; Fig. 6 illusi5. This tripping member is adapted to rest tratesatelephone switchboard position showing normally against bar member I2which acts as 50 the manner in which the time indicators may be a stoptherefor when-cam 5 is being restored to associated with the equipmentof a telephone its normal position. system. Clutch means E is in theform of a ribbon As shown in Figs. 1-5, the apparatus consists, spring.One end i6 thereof partially encircles in general, of a case I which isopen at the top, shaft ii and'is held firmly against one side of 55target member 22 by means of hinge spring 9. The other end ll of saidclutch means encircles shaft 3 at a point adjacent collar i8 of hub l3.Intermediate the ends i6 and i? the spring forming the clutch means isbent outwardly to form a flange i9.

Clutch control means I is T-shaped with one end of the top member beingbent upwardly as shown at 22 in Figs. 1 and 2. The vertical memberthereof extends downwardly through a slot in the top of target member 2and is pivoted to the sides thereof at 28. The lower part of saidvertical member is grooved so that it is capable of fitting over flangeIQ of clutch means 8. This groove is indicated at 2! in Figs. 2 and 4.Control means 'i is mounted on the target member in such position thatend 22 can be pressed down by the same movement by which said targetmember is pressed down and in such position that the vertical memberthereof is normally adjacent flange iii of clutch means 6.

The reset means consists of coil spring i wound around hub 93 betweencollar i8 and cam One end of spring ill is fastened to cam 5, and theother end is fastened to bar 23 of clutch means As stated above, Fig.dillustrates the manner in which the time indicator may be used inconnection with the equipment of a telephone system for measuringovertime on coin box calls. In said figure, t l indicates the primaryline jacks, 25 the multiple answering jacks, 25 the outgoing trunk jacksor the subscribers multiple jacks, depending upon the particular type ofswitch board, 2? the plugs of the cord circuits, 28 the cord supervisorylamps, 29 the coin control keys, and 38 the ringing and listening keys.The time indicators indicated at 3% are mounted side by side on the topof the key shelf, each time indicator being in alignment with the plugsof the cord circuit with which it is to be used. It will be noted byreference to Figs. 4 and 5, that the may be replaced or taken out at anytime.

driving shaft 3 of each time indicator has a male and a femaleend. Whenthe time indicators are mounted side by side on the lrey shelf, the maleend of shaft 3 of each time indicator is fitted in the female end of theshaft of the adjacent register. As a result, the several shafts of thetime indicators form a'common driving shaft which is divided into aplurality of sections with male and female ends, one section for eachregister. By reason of this arrangement any number of time indicatorsmay be used for each position of the switchboard, and any time indicatorThe male or female end, as the case may be, of one of the terminal timeindicators, is fitted in the female or male end, as the case may be, ofthe driving shaft of a continuously operated, constant speed motor 3E,for example, which shaft is connected to the mot-or through suitablegearing apparatus. Hence, shaft 3 and gear of each time indicator rotatecontinuously at a constant speed.

For convenience, the operation of the apparatus will be described inconnection with. the system disclosed for measuring overtime on coin boxcalls. As indicated in Fig. 6, the target member teeth of the cam.

tains the number of the party desired. She then inserts the calling plugin the proper one of the multiple jacks 26, or, in case trunk jacks areprovided, in one of the trunk jacks 26 which extends to an operatorhaving access to the called partys multiple jack. When the called partyanswers, the originating operator presses down end 22 of controlmeans 1. Since spring latch 8 is in engagement with bar member l2,target member 2 is held in its hidden position within case I inopposition to the force exerted by hinge spring 9. The operation of end22 of control means J to its operated position, causes the vertical armof control means i to press against flange S9 of clutch means 6 andforce end il' thereof against collar ll of hub l3. Flange i9 slips intogroove 2| of the vertical arm of control means 7 and both the clutchmeans and the control means are held in their operated positions. Thepressure of end ll of the clutch means against collar 28 causes hub i3and tripping cam to slide along shaft 3 against the force exerted byspring i4 until the teeth of the cam engage the teeth of the rotatinggear 5. Upon the engagement of cam 5 with driving gear 4, said cambegins to rotate at a constant predetermined speed with said gear andshaft 3. At this point, the shape and arrangement of the teeth of thecam and of the driving gear should be noted. By reference to 5 it can beseen that the forward edge of each tooth of the cam slopes downward,that the rearward edge of each tooth of the cam is straight orhorizontal, and that the teeth of the driving gear are so shaped andarranged that they will mesh with the teeth of the cam. Consequently, ifthe teeth are not in exact meshing position at the moment they come incontact with each other, the teeth of the rotating gear will slide alongthe sloping edges of the teeth of the cam and will not cause anymovement of the cam untilthey exactly mesh with the is a result of theshape and arrangement oi the teeth, any inaccuracy in timing, due to thefact that the teeth do not at once mesh, will be in favor of the partycharged. At the expiration of a predetermined interval of time cam 5will have rotated with gear I to such a position that tripping memberwill have come in contact with spring latch B and forced spring latch 6away from bar member 42. Upon the disengagement of the spring latch frombar member l2, hinge spring 9 becomes effective to cause target member 2to spring up suddenly from its hidden to its exposed position. Theupward movement of the target member slides the grooved vertical arm ofcontrol means 1 oh flange IQ of clutch means 8, and control means 7returns to its normal position as shown in Figs. 1 and 2. Clutch means 5is released and returns to its normal position. Spring ii becomeseffective to disengage cam 5 from gear 8. The rotation of earn 5 ceasesand coil spring to, which was wound up by the rotation of cam 5 withgear 6, immediately begins to unwind and cause cam 5 to rotate in theopposite direction until tripping member |5 comes in contact with barmember 12. The sudden movement of the target member from its hiddenposition to its exposed position, notifies the operator that the firsttiming period for the call has expired. calling party that his time hasexpired, and that if he desires to continue the call he must depositanother coin. II the calling party does not desire to continue the call,he disconnects and the operator uponreceiving the disconnect signaltaken The operator immediately notifies the down the connection andoperates the proper coin control key to collect the deposited coin. Onthe other hand, if the calling party deposits another coin, the operatorin one movement presses down the corresponding target member and end 22of control means I. The cycle as-described above, is repeated for theduration of the call.

If the call is terminated prior to the expiration of the first timingperiod, or of any subsequent timing period, the operator on receivingthe disconnect signal takes down the connection and operates. the coincontrol key as before, and then presses down the end of control means Iopposite to end 22. This moves the vertical arm of control means I outfrom under flange IQ of clutch means 6. Clutch means 6 is released andcam is restored to its normal position as before. Spring latch 8,however, still engages bar member l2, and target member 2 remains in itshidden position. When the cord circuit is used to complete another callthe operator upon the completion of the connection presses down end 22of the corresponding control means. This moves the grooved vertical armof control means 1 under flange IQ of clutch means 6 and operates'saidclutch means as before to cause the engagement of the cam and gear tostart the timing of the call.

It is obvious from the above description that the target members of thetime indicators may normally be maintained in their exposedpositionswith ends 22 in their up positions. In

,such a case, when a cord circuit is used to establish a connection, thetarget memberv and end 22 of the corresponding time indicator arepressed down in one movement to start the timing of the call.

Although this invention has been described in connection with atelephone system for measuring overtime on coin box calls, it is to beunderstood that it may be used in connection with telephone systems formeasuring other types of calls, and that the apparatus and featuresthereof may be used in connection with other systems than a telephonesystem to time any operation, without departing from the spirit andscope of the invention.

What is claimed is:

1. In combination, a motor, a plurality of rotatable elements, a commondriving shaft rotated by said motor and adapted to rotate said rotatableelements, means individual to each rotatable element adapted to causeonly the corresponding rotatable element to rotate with said shaft andto prevent the rotation of only said corresponding rotatable element, asdesired, means individual to said latter means for controlling its'operation, normally hidden means individual to each rotatable element.and means individual to and associated with each rotatable elementadapted to operate only the corresponding hidden means automatically toan exposed position when the corresponding rotatable element rotates fora predetermined timing period, said corresponding normally hidden meansbeing adapted to be reoperated manually to its hidden position aftereach timing period.

2. In combination, a motor, a plurality of rotatable elements, a commondriving shaft rotated by said motor and adapted to rotate said rotatableelements, means individual to each rotatable element for starting therotation of only the corresponding rotatable element with said drivingshaft and for stopping the rotation of only said corfesponding rotatableelement, as,

desired, normally hidden means individual to each rotatable element, andmeans individual to and associated with each rotatable element adaptedto operate only the corresponding normally hidden means automatically toan exposed position when the corresponding rotatable element rotatesthrough a predetermined distance. v

3. Incombination, a motor, a plurality of rotatable elements, a commondriving shaft rotated by said motor and adapted to rotate said rotatableelements, means individual to each rotatable element for effectivelyconnecting and disconnecting the corresponding rotatable element andsaid shaft to start and stop the rotation of only the correspondingrotatable element, as desired, normally'hidden means individual to eachrotatable element, means individual to each rotatable element andadapted, when the corresponding rotatable element rotates through apredetermined arc, to cause only the corresponding normally hidden meansto be operated to an exposed position, said corresponding normallyhidden means, during its movement from its hidden position to itsexposed position, operating the corresponding connecting anddisconnecting means to cause the effective disconnection of thecorresponding rotatable element and said shaft, and means individual toeach rotatable element and operative upon such disconnection to restorethe corresponding rotatable element to the position it occupied prior toits rotation.

4. In combination, a continuously operated constant speed motor, aplurality of rotatable elements adapted normally to remain stationary inpredetermined positions, a common driving shaft rotated by said motorand adapted to rotate said rotatable elements, said shaft being dividedinto a plurality of sections, one for each rotatable element, with maleand female ends, the male end of each said section being fitted into thefemale end of the adjacent section, clutch means individual to eachrotatable element for effectively connecting the corresponding rotatableelement with said driving shaft to start the rotation of thecorresponding rotatable element and for effectively disconnecting thecorresponding rotatable element therefrom to stop said rotation, asdesired, control means individual to each rotatable element foroperating and releasing the corresponding clutch means, a normallyhidden member individual to each rotatable element, means individual toeach rotatable element and adapted, when the corresponding rotatableelement rotates through a predetermined arc, to cause the correspondingnormally hidden member to spring suddenly into view, said correspondingnormally hidden member, during its movement from its hidden position toits exposed position, releasing the corresponding control means and thecorresponding clutch means to effectively disconnect the correspondingrotatable element from said driving shaft, and means individual to eachrotatable element and operative upon such disconnection to restore thecorresponding rotatable element to its predetermined position.

5. Means for timing the duration of telephone connections established ata central switchboard by means of a plurality of link circuitscomprising, in combination, a timing device for each link circuitincluding a timing wheel, a driving shaft common to said timing devicesand adaptedtorotatethetimingwheelsofsaidtiming devices, a motor adaptedto rotate said driving shaft, means individual to each timing device forstarting the rotation of the corresponding timing wheel with saiddriving shaft to measure the elapsed time of each telephone connectionestablished by means of the corresponding link circuit and for stoppingthe rotation of only the corresponding timing wheel, as desired,normally hidden means individual to each timing device, and meansindividual to and associated with each timing device adapted to operateonly the corresponding normally hidcien m ans automatically to anexposed position when the corresponding timing wheel rotates for apredetermined timing period, said corresponding normally hidden meansbeing adapted to be reopei'ated manually to its'hidden position aftereach timing period.

6. Means for indicating the number of timing periods of *elephoneconversations on connections established at acentral switchboard bymeans of a plurality of cord circuits comprising, in combination, atiming device for each cord circuit including a measuring wheel normallystationary in a predetermined position, a driving shaft common to saidtiming devices and adapted to rotate the measuring wheels of said timingdevices, a continuously operated constant speed motor for rotating saiddriving shaft continuously at a constant speed, clutch means individualto each timing device for effectively connecting the correspondingmeasuring wheel with said driving shaft to start the rotation of onlythe corresponding measuring wheel to measure the first predeterminedtiming period of each telephone connection established by means of thecorresponding cord circuit, control means individual to each timingdevice for operating and releasing the corresponding clutch means tostart and stop the rotation of only the corresponding measuring wheel,as desired, a normally hidden member individual to each timing device,means individual to each timing device and adapted, when thecorresponding measuring wheel rotates through a predetermined arc, tocause only the corresponding normally hidden member to spring suddenlyinto view, said corresponding normally hidden member, during itsmovement from its hidden position to its exposed position, releasing thecorresponding control means to the corresponding clutch means andeffectively disconnect the corresponding measuring wheel from saiddriving shaft, and means individual to each timing device and operativeupon such disconnection to restore the corresponding measuring wheel toits predetermined position, said corresponding normally hidden memberbeing adapted to be reoperated manually to its hidden position and saidcorresponding control means being adapted to be reoperated manually tostart anew the rotation of said corresponding measuring wheel after eachrestoration of said corresponding measuring wheel to its predeterminedposition, to measure each succeeding timing period of each telephoneconnection established by means of the corresponding cord circuit.

7. A timing device comprising, in combination, a rotatable elementnormally stationary in a predetermined position, a driving meansadapted, when said rotatable element is effectively connected therewith,to rotate said rotatable element, means for effectively connecting anddisconnecting said rotatable element and said driving means to start andstop the rotation of said rotatable element, as desired, normally hiddenmeans, means associated with said rotatable element and adapted, whensaid rotatable element rotates for a predetermined time, to cause saidnormally hidden means to be operated to its exposed position, saidnormally hidden means, during its movement from its hidden position toits exposed position, operating said connecting and disconnecting meansto cause the effective disconnection of said rotatable element and saiddriving means, and means operative upon such disconnection to restoresaid. rotatable element to its predetermined position.

8. A measuring device comprising, in coinbina tion, a driving means, arotatable element adapted to be rotated by said driving means, means forstarting the rotation of s d rotatable element with said driving meansand etc said rotation, as desired, means hidden from view when therotation of said rotatable element begins, and means associated withsaid rotatable element and adapted to operate said hidden means to anexposed position when said rotatable element rotates through apredetermined arc.

9. Measuring apparatus comprisingin. combination, a rotatable elementnormally stationary in a predetermined position, a driving meansadapted, when said rotatable element is effectively connected therewith,to rotate said rotatable element, means for effectively connecting anddisconnecting said rotatable element and said driving means to start andstop the rotation of said rotatable element, as desired, normally hiddenmeans, means associated with said rotatable element and adapted, whensaid rotatable element rotates through a predetermined arc, to causesaid normally hidden means to be operated to an exposed position, saidnormally hid-- den means, during its movement from its hidden positionto its exposed position, operating said connecting and disconnectingmeans to cause the effective disconnection of said rotatable element andsaid driving means, and means operative upon such disconnection torestore said rotatable element to its predetermined position.

10. A measuring device comprising, in combination, a driving shaftadapted to rotate continuously at a constant speed, a gear rotated bysaid driving shaft, 9. driving means for rotating said driving shaftcontinuously at a constant speed, a measuring wheel normally stationaryin a predetermined position and adapted to be rotated by said gear whensaid wheel and said gear .are in engagement with each other, clutchmeans for causing the engagement of said wheel and said gear and thuscausing the rotation of said wheel by said gear, control means foroperating and releasing said clutch means to start and stop the rotationof said measuring wheel, as desired, a member associated with saidcontrol means and adapted to be hidden from view when said control meansis operated, means associated with said measuring wheel and adapted,when said measuring wheel rotates through a predeterminedarc, to causesaid member to spring suddenly into view, said member, during itsmovement from its hidden position to its exposed position, releasingsaid control means and said.

clutch means to disengage said measuring wheel and said gear, and meansoperative upon said disengagement to restore said measuring wheel to itspredetermined position.

11. A measuring device comprising, in combination, a case which is openat the top, a target member positioned within said case and hinged atone' end of said case, a hinge spring tending to cause the opposite endof said target member to protrude from the top of said case, a drivingshaft adapted to rotate continuously at a constant speed, a gear withinsaid case rotated by said driving shaft, a driving means for rotatingsaid driving shaft continuously it a constant speed, a trippin camnormally stationary in a predetermined position and adapted to berotated by said gear when said cam and said gear are in engagement witheach other, clutch means for causing the engagement of said cam and saidgear and thus causing the rotation of said cam with said gear, a barmember fastened to said case, a spring latch connected to said oppositeend of said target member and adapted, when said opposite end is presseddown, to engage said bar member andhold said opposite end within saidcase against the force exerted by said hinge spring, control meansmounted on said target member for operating and releasing said clutchmeans to start and stop the rotation of said cam, as desired, a trippingmember connected to said tripping cam and adapted, when said cam isrotated through a predetermined arc, to disengage said spring latch fromsaid bar member and permit said opposite. end of said target member tobe operated to a protruding position above the top of said case, saidopposite end of said target member, during its movement to itsprotruding position, releasing said control means and said clutch meansto disengage said cam and said gear, and means operative upon suchdisengagement to restore said cam, to its predetermined position.

12. A time indicator comprising, in combination, a case which is open atthe top, a target member positioned within said case and hinged at oneend to said case, a hinge spring tending to cause the opposite end ofsaid target member to protrude from the top of said case, a drivingshaft adapted to rotate continuously at a constant speed, a crown-gearwithin said case mounted on and rotated by said driving shaft, a drivingmeans for rotating said driving shaft continuously at a constant speed acrown-gear tripping cam rotatably and slidably mounted on said shaftadjacent said gear, clutch means associated with said cam for causingsaid cam to engage said gear and be rotated thereby, the teeth of saidcam and of said gear being of such shape with respect to each other thatsaid cam does not begin to rotate until said teeth fully mesh, a barmember fastened near the bottom of said case and extending toward thecenter thereof, a spring latch connected to said oppo-- site end of saidtarget member and adapted, when said opposite end is pressed down, toengage said bar member and hold said opposite end within said caseagainst the force exerted by said hinge spring, control means mountedon'said target member for operating and releasing said clutch means tostart and stop the rotation of said cam, as desired, said control meansbeing mounted on said target member in such a position that it can beoperated by the same movement by which said opposite end of said targetmember is pressed down, a tripping member connected to said tripping camand adapted, when said cam is rotated through a predetermined arc, todisengage said spring latch from said bar member and permit saidopposite end of said target member to be operated to its protrudingposition above the top of said. case, said opposite end of said targetmember, during its movement to its protruding position, releasing saidcontrol means and said clutch means, a spring mounted on said shaftbetween said gear andsaid cam and operative upon the release of saidclutch means to disengage said cam from said gear, and a coil springassociated withsaid cam and operative upon such disengagement of 'saidcam to restore adapted, when released, to protrude from the top of saidcase, a rotatable element within said case, a driving means adapted torotate said rotatable element, means for starting and stopping therotation of said rotatable element, as desired, means associated withsaid rotatable element and adapted, when said rotatable element rotatesthrough a predetermined arc, to release said opposite end of said targetmember, and means operative upon the release of said opposite end ofsaid target member to cause said end to operate to a protruding positionabove the top of said case. I

14. In combination, a motor, a plurality of rotatable elements, a commondriving shaft rotated by said motor and adapted to rotate said rotatableelements, means individual to each rotatable element for starting therotation of only the corresponding rotatable element with said shaft andfor stopping the rotation of only said corresponding rotatable element,as desired, normally hidden means individual to each rotatable element,and means individual to each rotatable element and adapted, when thecorresponding rotatable element rotates through a predetermined arc, tocause only the corresponding normally hidden means to be operated to anexposed position, said corresponding normally hidden means, during itsmovement from its hiddenposition to its exposed position, operating thecorresponding connecting and disconnecting means to cause the effectivedisconnection of the corresponding rotatable element and said shaft.

15. Means for timing the duration of telephone connections establishedat a central switchboard by means of link circuits comprising incombination, a. plurality of timing devices, one for each link circuit,a driving shaft common to said timing devices and adapted to operatesaid timing devices when said timing devices are effectively connectedthereto, a motor for rotating said common shaft, means individual toeach timing device for effectively connecting and disconnecting only thecorresponding timing device with said driving shaft to start thecorresponding timing device into operation for measuring the elapsedtime, in terms of predetermined timing periods, of each telephoneconnection established by means of the corresponding link circuit and tostop the operation thereof, as desired, normally hidden means individualto each timing device, and means individual to each timing device andadapted, when the corresponding timing device operatesifor apredetermined timing period, to cause only the correspondingnormallrhidden means to operate to an exposed position, saidcorresponding normally hidden means, during its movement from its hiddenposition to its exeffectivedisconnection of the corresponding tim s d vie and said shaft. a a

. EMIL N. ANDERSON.

